Children's Hospital Oakland Research Institute (CHORI) is a free-standing institute that serves as the research arm of the Children's Hospital & Research Center Oakland. Our research program is among the top pediatric research departments in the nation with regard to funding from the National Institutes of Health (NIH). Research is heavily focused on lipids and lipoproteins in health and disease. This proposal requests funds to purchase an Agilent 6490 Triple Quadrupole mass spectrometer (MS) equipped with 1290 Infinity Quaternary liquid chromatography (LC) system. This LC/triple quadrupole MS combined system would replace an out-of- date LC/MS system that is rapidly approaching the end of its lifespan. LC/MS instrumentation is a critical resource for a large and diverse array of research projects involving metabolomics, analysis of biomarkers of disease and inflammation, drug delivery using nanotechnology, lipid quantitation, and analysis of lipid-binding proteins. The instrument would be used to quantify target molecules including sphingolipids, vitamin D, amino acid metabolites, thiolated and oxidized proteins, phospholipids, oxysterols and metabolites of statin drugs. Twelve major users representing a cross-section of CHORI's major scientific centers, including Cancer Research; Sickle Cell Disease & Thalassemia; Nutrition & Metabolism; Immunology & Vaccine Development; Prevention of Obesity, Cardiovascular Disease & Diabetes; and Genetics will be supported by the instrument. The 6490, with iFunnel Technology, enables zeptomole detection limits at conventional HPLC flow rates. The 6490 instrument provides unsurpassed sensitivity for the analysis of pharmaceutical compounds, trace-level nutrients, clinical samples, drugs, metabolites, and biomarkers. With 1 millisecond dwell times and no collision cell cross talk, the 6490 QqQ is ideally coupled with the 1290 ultra high-pressure/performance LC (UHPLC) system for fast sample analyses, allowing reliable peak integration and quantitation across even 1 second-wide UPHLC peaks. For very complex sample mixtures, the 6490 QqQ allows dynamic multiple reaction monitoring (MRM) methods with up to 4,000 transitions per method and polarity switching in as little as 30 milliseconds. The Agilent 6490 QqQ is a versatile, state-of-the-art instrument with high sensitivity, linearity, dynamic range, reproducibility and robustness and which represents a technology with which our user group is highly familiar. Thus, we have chosen this as the optimal system from a number of competing MS systems. The new LC/MS system will significantly advance the current projects and add to the pool of shared equipment at CHORI. CHORI's scientists are adept at LC/MS; we have long-standing experience in pioneering MS technology and maintaining an active MS Core Facility. We have also recruited external scientific advisors to further insure the instrument is utilized properly and to the highet capacity possible for innovative research by the largest number of CHORI investigators and potentially by external investigators through collaborative research endeavors.